Air or gas compressor



l Aug. 30, 1932. sf R. HlRscHA AIR OR GAS COMPRESSOR Filed June 15. 1930 Patented Aug. 30, 1932 4' UNITED sTATEs PATENT vOFFICE- sYLvAN n. HInsCH, or CINCINNATI, omo, AssIGNon 'ro won'rHINefroN PUMP AND MACHINERY ConroaA'rroN, or NEW Yonx, N. Y., A CORPORATION or VIRGINIA' .AIR OR GAS COMPRESSOR Application led .Tune 18,

submerged in a vacuum which effects its perp formance, causing spasmodic o'r interrupted oil delivery and consequently ineiiicient lubrication of the wear surfaces of the compressors with the resulting inefficiency of operation and decrease in the life of the compressor.

Also in compressors of this type, the pressure in the crankcase when below atmosphere, may permit the inrush 'of atmospheric air through the shaft packing or crankcase entrance thereby reducing the eficiency of the system.

It is an object of the present. invention to provide a line of communication between the enclosed crankcase compressor in which line of communication is located a pressure operated relief valve, tensloned to maintain a predetermined pressure in the crankcase of the compressor to overcome the undesirable features above pointed out and insure efficient operation ofthe 'lubricating oil pump as well as prevent the inrush of atmospheric air into the crankcase and also to provide means whereby said automatic pressure operated relief valve may be rendered inactive for the purpose specified at certain times or under certainrconditions.

With these and' other objects in view, as may appear from the accompanying specification, the invention consists of various `features of construction and combination of parts, which will be irst described lin connection with the accompanying drawing, showing a compressor of the preferred form embodying the invention, and the features l port or passage 8.

1930. Serial F0. 460,812.

forming the vinvention will be pointed out in the claims. f l

In the drawing y Fig. l is a vertical section through a compressor embodying the present invention.v

Fig. 2 is an enlarged fragmentary section speeically of the automatic or pressure operated relief valve. Referring more particularly to the drawing, a vertical air or gas compressor of the crankcase type is shown .in the drawing but itis' to be understood that the present invention may be used'in connection with any aproved type of enclosed crank compressor without departing from the spirit of this invention.y The compressor 1 comprises the usual'cylinder 2 in which the piston 3 reciprocates for compressing the Huid, which is drawn into the l cylinder through the suction valve structure 4, suction chamber 5 and suction or inlet port 6, while it is discharged from the cylinder through the discharge valve 7 anddischarge The crankcase 9 of the compressor is enclosed so as to prevent leakage to atmosphere of any fluid or gas which might leak past the crankcase and suction port or chamber of ?piston 3 into the Ycrankcase and to prevent the and 13, which are positioned eXteriorly ofthe compressor although it is to be understood that this line of communication may be within the compressor casting itself or at any other suitable location without departing from. the spirit of this invention.

To prevent the compressor suction from lowering the pressure in the crankcase to the degree/of pressure whereby it will interfere i with theo eration of the lubricatingpump 4(notshown i, a pressure 'relieii valve structure 14 is connected -in the line of communication petween the crankcase 9 and the suction chamv.The pressure relief valve struc-ture 14 in cludes a valve seat in the line of communi` cation against which the valve. 16 is urged and held seated by the spring 17 The spring 17 engages the disc 18 which is positioned against one side of the diaphragm 19,'While i the valve 16 engages the opposite side of the diaphragm and is held tightly in engagement, therewith by means of the spring 20. The diaphragm. 1'9 forms one wall of the chamber 21 within the reliefvalve structureilli and this chamber 21 opens into the crankcase 9.

,. 'crankcase 9 to the suction chamber 5, which will permit the compressor to suck or draw the gas, air or the like from the crankcase 9 v for recompression. When the pressure in the crankcase 9` fallssuiiiciently or less than the tension of the spring 17 the spring will A act to seat the valve 16 and cut o-the communication between-the suctionof the compressor in the crankcase 9 until such time as l the tension re any -approved-type' of ,valve preferably'a VLThe combination with an compressor of the'enclosed crankcas'e. typel the pressure'in. the crankcase again exceeds the tension of the' spring 17.

The tension of the spring 17 may be regulated as desired to vary the pressure requirements-for unseating the valve 16 by means of lator structure22, which is of the usual ad]u'stable bolt and disc type as shown in Fig. 1.

^ At times it is desirable to open theol-ank-l casef9 tothe suction of the compressor irrespective of the pressurein thev crankcase and consequently 'render' the relief valve 14 inac tive for the purpose for which it isJ devised and to permit such operation, a bypass ar.

,i rangement is provided.

in Fig; 1 ofthe drawing, this'bygass Aarrangement comprises a pipe 2 3, which opens into thechamber 21 andiinto a valve,24:,'.which is connected by means of apipe 25 -lwith the pipe12 and when the valve cone 26 Aof 'the valve 24 is unseated, a bypass arrangement around the valve16 is provided; however,

when the valve cone 26 is seated, such b'v ass Gif* y'pressure at which the valve opens or c oses,v

is cut off; The valvestructure 24 .may

manually operated valve in whichthe cone 26 is' seated or unseated. by rotation: of the It will be understood that the invention is not to be limited to the s ecific construction or'arrangement of parts s own but that they ma be widely modified within the invention Levens.

compressor, said discharge port being free from connection with said crankcase of a pressure actuated valve acted u on by the pressure within the crankcase or opening and closing said. passage, and adJustable means cooperating with said valve -to tension the valve to permit regulation of the pressure at which the valve opensor closes, a bypass about said pressure actuated valve to permit communication between the compressor suction port and the crankcase irrespective 'of the pressure actuated valve', and a valve in said bypass.

2. In an air or gas compressorembodying suction and discharge' ports and an enclosed crankcase,said discharge port being free from connection with said crankcase whereby the fluid compressed by the compressor will not enter the crankcase, and pressure actuated means operable upon creationlof a predetermined pressure in the crankcase to open communication between the crankc'ase and suction port for lowering the pressure in the crankcase.

3. In an air or gas compressor embodying crankcase, said dischar e port being from connection with lsai l`crankcase w e the Huid compressed bythe compressor will .not enter the crankcase, a pressure actuated:

valve operable upon .creation of. a predeterlmined pressure in the crankcase to open communication between the crankcase and suction port for lowering the .pressure in the crankcase, and adjustablemeans for regulatingthe tension of said. valve for regulating 'the pressure at which the valve -opens or closes'.l v p 4. In an air or gas compressor embodying suction and discharge ports 'and an' enclosed cranl'zca'ise,l said dischar e port being free from .connection with said crankcase whereby the Huid compressed by the compressor .will notenter the crankcase, a pressure actuated valve operable upon creation of a predetermined pressure in the crankcase 'to open .communication between theI4 crankcase and suction port for lowering the pressure in the.

c'rankcase, ad'ustable means for regulating the tension o said valve for regulatin the and manually controlledmeans for opening -the'suction chamber towthe crank'case irre-v spective. of said pressure actuated means. A. In 'testimony whereof'I ax my signature. y SYLVAN R. HIRSCH.

airfor i having suction'and discharge ports and hav'- I f i'ng a passage establishin communication between the. crankcase an suction port. ofthe A 

